<!DOCTYPE html>
<html lang="zh-cn">
    <head>
        <meta charset="UTF-8"/>
        <meta name="viewport" content="width=device-width, user-scalable=no, initial-scale=1.0, maximum-scale=1.0, minimum-scale=1.0" />
        <meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1" />
        <title>小图标与文字垂直居中对齐</title>
        <style>
            * {
                padding: 0;
                margin: 0;
            }
            
            .close-btn {
                display: -webkit-box;
                display: box;
                display: -webkit-flex;
                display: flex;
                -webkit-box-align: center;
                box-align: center;
                -webkit-align-items: center;
                align-items: center;
                background-color: #00BB9C;
                width: 80px;
                height: 40px;
                margin: 30px auto;
                -webkit-border-radius: 6px;
                -moz-border-radius: 6px;
                border-radius: 6px;
            }
            
            .icon-close-hmc {
                display: block;
                background-position: center;
                background-repeat: no-repeat;
                background-size: contain;
                background-image: url("http://s1.mi.com/m/images/20151028/top-x.png");
                width: 16px;
                height: 16px;
                margin: 0 10px;
            }
            
            .close-txt {
                font-size: 16px;
                color: #FFFFFF;
            }
        </style>
    </head>
    <body>
        <div class="close-btn">
            <i class="icon-close-hmc"></i>
            <div class="close-txt">
                关闭
            </div>
        </div>
    </body>
</html>